It is well known to provide a support mechanism including a four bar or parrallelogram linkage to support an art device, such as a keyboard, for vertically swinging movement relative to a base, such as a wall, desk top or table top, between lower and upper use positions; and a locking device to releasably retain the art device in a desired position. Typically, the linkage includes upper and lower links, a first end link for mounting a keyboard support, a second end link fixed to the base and pivot connections for pivotally connecting the ends of the links for pivotal movement about four parallel pivot axes; and the locking device includes a pair of cooperating members carried by the links.
In a commonly assigned patent application entitled KEYBOARD MOUNTING MECHANISM and filed Nov. 5, 1998, there is disclosed an improved mechanism, wherein a parallelogram linkage is pivotally mounting by one of its pivot connections on a separate base mounting member, and a locking device includes members carried by the linkage and mounting member.